Our society is becoming increasingly health conscious and products relating to fitness are becoming increasingly popular. As such, there exists a large body of related art relating to fitness aid devices coupled to biofeedback technology. For example, there are currently devices that use a wrist-watch-type monitor to inform the user, through an audible beep signal or display screen, when their heart rate is in a target zone, ideal for aerobic exercise. This target zone calculation is based on the output of a heart rate monitor, the user's age and gender. Many of these devices include a chest belt that contains a heart rate sensor. These belts can be cumbersome and uncomfortable for the user. They also require some form of perspiration to operate reliably, as the sensor needs a conductive process to detect the heartbeat on the surface of the epidermis.
There are also wrist-watch-type fitness aid devices that detect the heart rate using a sensor attached to the user's finger or directly to the user's forearm (U.S. Pat. No. 4,295,472). Such devices do not require the end-user to wear a chest-belt sensor. However, the user must view the device on his wrist or rely on vague audio cues to read any pertinent physiological data, which would be impractical in many exercise scenarios (i.e. running or jogging). Furthermore, wrist-based audio systems generate relatively low-sound-pressure-level audio cues that easily can be masked, rendering them inaudible in many exercise environments. The user is thus forced to view the wristwatch in order to determine how they are performing during their exercise program. Also, wristwatches can become damaged and lose some of their visual display clarity, thus compromising their usefulness.
Many methods exist for monitoring the physiological attributes of a user under normal conditions, under distress, and in other states of homeostasis. Advances in the noninvasive detection and analysis of cardiovascular and respiratory patterns in living subjects provide a variety of cost-effective, efficient options for measuring physiological data. Examples include non-invasive ultrasound techniques, which have been developed to accurately measure blood flow. Pulse oximetry technology provides a simple method for monitoring the oxygenation of a patient's blood by simply attaching a device to the fingertip or earlobe of the user.
Similarly, photoplethysmography (PPG) sensors use visible or near-infrared radiation and the resulting scattered optical signal levels to monitor the blood flow waveforms, which can be transformed into heart rate data. PPG devices are typically attached to the patient's lobule (earlobe) or fingertip (U.S. Pat. No. 7,044,918). These devices are effective, inexpensive, and reliable under most circumstances. Furthermore, they do not rely on conduction and as such are far more practical for exercise.
PPG devices provide an appropriate means for implementing pulse wave detection and heart rate monitoring. Furthermore, one of the most practical areas of the human body to place a PPG sensor is near the lobule (earlobe).
A wide variety of methods for converting physiological data into meaningful information relevant to personal fitness have been developed. These include calculations of caloric burn data from heart rate data, pedometer data, or other physiological data. Also, the calculation of a target heart rate zone or zones is widely implemented in fitness aid devices. Such calculations are usually based on averages corresponding to an individual's age and often gender, although more sophisticated methods exist as well (U.S. Pat. No. 5,853,351).
Further related art discusses a system similar to the present invention that requires fitting of a sensor in the ear of the user (U.S. Pat. No. 6,808,473). However, this is a more impractical approach, requiring a setup process to align the sensor's optics with the superficial temporal artery to allow detection of the user's pulse waveform.
Several hearing aid companies have developed behind-the-ear (BTE) devices, and have a history in the hearing aid community of robustness and stability under many forms of physical exercise without the BTE unit detaching and falling away from the user's ear.
For many people, exercise is not enjoyable. These people do not exercise as a routine part of their daily lives. Since they do not enjoy it, they tend not to be compliant. In response, music has often been used to motivate and energize people while exercising. Since the introduction of aerobic dance in the early 1970's, it has generally been regarded that music accompaniment to exercise provides significant beneficial effects to the exercise experience. Although the relationship between physiological benefits and music is not necessarily supported by rigorous scientific study, the perceived benefits and motivational benefits are confirmed by simply observing a typical health club environment. In the health club, many individuals chose to wear earphones and upbeat music is often played over the loudspeaker system. Also, music selection is considered paramount in a wide variety of exercise classes. The physiological benefits of the addition of music to exercise scenarios might not be scientifically proven, however the motivational benefits are obvious.
It should be noted that not all exercise is good. Too much exercise can be unhealthy. The appropriate intensity and duration of exercise vary with age, physical strength, and level of fitness. In addition, for those engaged in self-monitored exercise programs recommended by physical therapists, there is a particular need for feedback regarding the extent to which individuals should push themselves.
Related art suggests that an appropriate method of informing an individual about their appropriate level of exercise relates to the AT (anaerobic threshold) value. Technically, the AT is the exercise intensity at which lactate starts to accumulate in the blood stream. Ideal aerobic exercise is generally considered to be around 80% of the AT value. Accurately measuring the AT involves taking blood samples during a ramp test where exercise intensity is progressively increased. Generally, in a consumer fitness aid device the AT value is measured using a less accurate but more practical method. Instead of blood samples, the device reads and analyzes the user's pulse wave during a ramp test (U.S. Pat. No. 6,808,473).